The Resurrection, Cookham, has been unfairly slammed as a cranky cartoon.

My favourite gallery is in Cookham, Berkshire. Drive into the village, and you could be forgiven for thinking you were in another era. The old high street still has Tudor buildings, cottages covered in wisteria - even the upmarket Indian restaurant fits in. The town's most famous son, the painter Stanley Spencer, would hardly notice the 21st century.

But the Stanley Spencer gallery - a few square metres of converted Methodist chapel - is closed for refurbishment, due to open in August. What hellish modernism are they going to bring to the gallery? It was primitive to say the least - a few paintings, sketches, some memorabilia plus postcards and prints to buy. It took about three minutes to go round. But it was the best place in the world - and I made my pilgrimage a few times a year.

Is Spencer's reputation being revamped, too? I am not sure. Lists of the worst artworks of the past hundred years (or ever) are trawled out every so often and - disaster! - Spencer's paintings keep hitting the top 10. Spencer's reputation is that he was a twee sentimentalist, a parochial brush-twiddler with an incomprehensible wish to represent his home town as "heaven on earth".

It is entirely wrong. Stanley was a man charged with passion, and his paintings were considered highly controversial during his lifetime. Here was the man that unceasingly catalogued family life with something as close to religious ecstasy as you can get. He painted domestic minutiae - cleaning, tidying up clothes - with all the reverence of a Giotto fresco.

His interest in painting scenes from Jesus's life soon turned into an obsession with re-staging scenes from the New Testament in Cookham itself. Forget Blake's fancy that Jesus must have taken a mini-break in Blighty during his short, holy life - Stanley had Christ preaching from a boat at the local regatta or carrying the cross past a house in the high street.

When Spencer divorced his first wife Hilda, he married a woman called Patricia Preece but the union was never consummated. She lived in his house with her lesbian lover (so it seems) and he painted some of the best pictures of his life, a series of nudes. They are graphic, stuttering, frustrated portraits with Stanley, emasculated, next to Patricia the hard-faced harridan.

That Spencer was a visionary is not in doubt. No it's not. When he wasn't painting he would write prolifically - letters, notes, monologues - in praise of (his own) painting, God, women and art. He liked writing on toilet paper because the apparently endless flow suited his thought process. He lived and worked in Cookham until he died, at the age of 78, carrying his art materials around the village in an old pram. He was never part of a great salon, but his influence is seen in Lucien Freud's work and even John Bratby's portraits of domestic muddle.

He chose to interpret everyday life as something beatific. It had nothing to do with depicting the common man and his toils as "good" and "earthy" as was traditional in figurative art. The common man, to Stanley, was probably yer actual God. Or at least a lustful sort, having an affair with a lesbian.

Stanley tried to reunite with his first wife after his second marriage failed, and he nursed her through mental illness until her death in 1950. His greatest ambition, the pinnacle of a lifetime's work, was a devotional chapel he would dedicate to each of his great loves, fusing the sexual with the spiritual. He died in 1959 before the project was realised. Those last years were spent painting landscapes as Spencer fell further out of vogue.

Spencer was a war painter. He ate jam sandwiches all day. He was obsessive and demanding. His eccentricity does, alas, overshadow his fine skill as a painter. I can only hope that the gallery opens soon, and is as fusty and unshowy as it always was.